div {
    height: 800px;
    margin-bottom: 50px;
    border: 1px solid red;
}

h2 {
    text-align: center;
}


td {
    border: 1px solid blue;
}

#loginNumber {
    border-radius: 5px;
    border: 2px solid blue;
    font-size: 20px;
    position: fixed;
    width: 150px;
    left: 20px;
    text-align: center;
}

table {
    width: 600px;
    border: 1px solid blue;
    border-collapse: collapse;
    margin: 100px auto;
    font-size: 22px;
}

table td, table th {
    border: 1px solid blue;
    padding: 10px;
}

#tab_log {
    margin: 200px auto;
}

ul {
    border: 1px solid blue;
    list-style: none;
    /* 取消列表样式 */
    text-align: center;
    font-size: 20px;
    background-color: #cccccc;
    padding: 10px;
}

ul li {
    display: inline;
    /* 更改 li 为行标签 */
    margin: 10px;
    background-color: #ffffff;
    min-width: 60px;
}

.show{
    display: block;
}
.hide{
    display: none;
}